Improve spelling of "notification".

ash/system/tray/system_tray_unittest.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ash/system/tray/system_tray.h"
 
 #include <vector>
 
 #include "ash/accessibility_delegate.h"
 #include "ash/root_window_controller.h"
@@ skipping 294 matching lines @@
 
   // Ensure a notification view is created.
   tray->ShowNotificationView(test_item);
   ASSERT_TRUE(test_item->notification_view() != NULL);
 
   // Show the default view, notification view should remain.
   tray->ShowDefaultView(BUBBLE_CREATE_NEW);
   RunAllPendingInMessageLoop();
   ASSERT_TRUE(test_item->notification_view() != NULL);
 
-  // Show the detailed view, ensure the notificaiton view remains.
+  // Show the detailed view, ensure the notification view remains.
   tray->ShowDetailedView(detailed_item, 0, false, BUBBLE_CREATE_NEW);
   RunAllPendingInMessageLoop();
   ASSERT_TRUE(detailed_item->detailed_view() != NULL);
   ASSERT_TRUE(test_item->notification_view() != NULL);
 
   // Hide the detailed view, ensure the notification view still exists.
   ASSERT_TRUE(tray->CloseSystemBubble());
   RunAllPendingInMessageLoop();
   ASSERT_TRUE(detailed_item->detailed_view() == NULL);
   ASSERT_TRUE(test_item->notification_view() != NULL);
@@ skipping 152 matching lines @@
 
   const views::View* settings =
       tray->GetSystemBubble()->bubble_view()->GetViewByID(
           test::kSettingsTrayItemViewId);
   ASSERT_TRUE(settings);
   EXPECT_TRUE(settings->visible());
 }
 
 }  // namespace test
 }  // namespace ash